iPhone connects and disconnects from Mac

Someone had this answer above but it wasn't explained well so like most of you I scrolled by. I tried in this thread and it didn't work. But this did! Open the Terminal app from Spotlight (Command+ Space) and enter the command sudo killall -STOP -c usbd

Yeah, it's that easy.

This will pause the usbd process. Now, connect the USB cable and check if the iPhone is still charging on and off rapidly.

I've had this problem for YEARS. I'm so glad it's fixed!

What worked for me; unplugging the cable from the Mac, plugged the cable into the phone first (iPhone 12), then plugged it back into the USB port on the computer, for whatever reason, that corrected it for me. Prior to this quick fix, it did not matter how many times I plugged my phone in, it would just show charging then not charging over and over.

I have an iPhone X and MacBook Air. I have done everything and nothing fixed it. Tried this and seems right. I hope Apple figure it out and fix it in new updates, however, I've seen that people have had this problem from 2013.

Re: Why does my iPad keeps connecting and disconnecting from the new late 2013 iMac

Hey everyone,

I just wanted everyone to have the solution here that way when others experience it, they can hopefully find this solution quickly. Luckily several of you like (MrArifFikri) touched on the solution already, I'll just specify the reason for clarity.

It comes down to power, or more importantly "current". Specifically, with an iPad, USB power consumption is very finicky. So in order for the USB direct connection to your PC, USB hub, or laptop you need to make sure your iPad is charged to over 51%. This will reduce the power draw the iPad will attempt to pull from the USB connection. This should give you flawless charging and syncing capabilities. Now you can sidestep this in some cases by using USB ports on your hub, PC or laptop that are closer to the power supply, or series on the circuit board.

If your iPad is below 51%, you need to use the "cube" or power block that came with your iPad. (The smaller one for your iPhone is not recommended as it lacks the internal transformer that the iPad power block has) The reason for this is that your iPad is attempting to draw too much current from the USB connection through a substrate, i.e. the PC, USB hub or laptop connection. They are only designed to allow a limited amount of current through those connections, thus your iPad continues to "trip" the charging circuit in the device because the power draw is too low.

I hope this helps stop the "doodledee.....deeedledoo" beeping madness you're experiencing! 🙂

Killing usbd in terminal worked for me.

Thank you so, so, so, so, much. I've been dealing with this issue for over a year. I appreciate it.

Try putting your phone into low power mode. That worked for me.

Never mind, rpmartins response using terminal solved it for me: https://discussions.apple.com/thread/8276949?answerId=33910238022#33910238022

For me it didn’t work . Updating OS solved as issue seemed to be with itunes

thanks

@Apple Please do something about it, I've tried everything other users have mentioned and it still doesn't work as it should (only thing that helped temporarily was going in the Activity monitor and quitting usbd process, but when I unplugged the iPhone and plugged it back in, the same error). I believe that I'm not the only one who is having this issue. Yes I'm using genuine Apple cable and yes I do know that you rather sell more phones than solving this issue which occurs to some users. Do something about it, for your customer's sake!

I have the same problem. I tried doing things below, but it didn't work.

The problem was fixed when i switched from a third party usb cable to one made by apple and pushed the end of the charger a little. Before that, i was using an anker charger(tried doing ^ but it didn't work).

The small battery symbol on the top right of my iPad was going on and off, so I thought that there was some problem with the connection from the usb cable to the computer.

Cleaning out the hole that the usb goes in, or pushing the usb end a little next to the computer's input will cause the cable to have a secure connection from the pc/laptop to your iPhone/IPad.

i hope this works for you.

from THISISYOURANSWER: Connect your iphone to your Mac.

Go to Activity Monitor --> Search for usbd --> Force quit it.

only solution that worked for me!!!! after digging into the comments. thank you!

using an iPhone XS Max and a Macbook Air.

golly. i even bought a new cable! thought it was the cable.

thank you @thisisyouranswer . xxx

I have tried literally everything I read on internet and still couldn’t fix it, so I turned off my macbook and turned it back on while iphone was still plugged in and it connected and stayed connected..when I unplugged it and tried it again it kept doing the same connecting/disconnecting thing. So I would suggest just restart your MacBook while iphone is still plugged in on the usb port and see if it solves the issue when it turns back on.

That is genius Arashk B. It’s a very frustrating problem that a lot of people are experiencing. Using my troubleshooting abilities developed through years of computer programming I had arrived at the same conclusion. I had determined that it’s a software based problem because the lightning cables that people are using are working everywhere else and the USB ports on their MacBooks are working with other USB devices. So there’s a bug in the OS (or it’s written that way) so when the power is low on the attached USB device MacOs will automatically send a disconnect to the USB port. Then the OS does what it was designed to do: it detects there’s something in the USB port and connects again! I’m communicating through Apple and some of my IOS app developers to see if there’s a work around.

I had the EXACT SAME ISSUE!!

Open iTunes on your MacBook,

click the “ITunes” option on the task bar (too right side of screen)

Preferences > Devices > then uncheck “Prevent iPhones from syncing”

Now just plug in your device and trust your MacBook !!

Abra!! Kadabra!!

In addition to what others have stated - I have had a couple of my laptops usb port get slightly loose and basically go out one didn't get loose and would not work for almost every usb device plugged into it but would on one or two... my other port worked continually for the life of those computers. SEE if it's in there firmly, try another usb port like a battery pac - and also consider the cords DO go out, even if new - I recently had two new ones go out - one after a few days and another after a few weeks.

Dear all, I have had this problem 3 months ago, then I thought I had been clearing it by only using my 2017 MacBook Pro instead of my 2016 MacBook Air, the phenomenon happening on the MacBook Air only. Yesterday I used my MacBook Air again as Nd the bloody on/off triggered again. I collected all the iPhone USB cables in the house and tried them one by one. In my case, it is defining USB cable that’s wrong. Only the most recent ones work properly. I have cut and binned all the defective ones, 6 out of 10 . Hope this helps